I just found out a little while ago while going over the car really close that my rear main seal is leaking like a stuck pig. So needless to say I have to drop the transmission to get that issue resolved. The transmission has about 102,xxx miles on it so while it's out shoud I get it rebuild or fix the seal, stick the transmission back in and drive it till it breaks? No issues with the transmission other than a slight whine / high pitched hum while driving.